Dilatation catheter

Abstract

A dilatation catheter having an outer tubular balloon portion with length-wise circumferential crimps having at either end transition portions with longitudinal crimps across the axis and an inner catheter is provided. The distal transition portion is fastened to the distal end of the inner catheter tube which extends beyond the distal end of the outer tube and the balloon portion while the proximal transition portion is connected tot he distal end of the outer catheter tube. The balloon portion expands readily to a predetermined diameter while undergoing little change in length with an extension of the transition portions so that relative movement of the inner and outer catheter tubing is not required. Accordingly, minimum shear forces occur at the interface of the expanded balloon surface and the interior vessel wall.

What is claimed is: 
     
       1. A dilatation catheter, comprising: a length of a tubular shaft of flexible material having a longitudinal axis;   an inner tubular flexible member coaxially disposed in the shaft and having a distal portion projecting therefrom;   a balloon portion formed at the distal end of the flexible shaft, the balloon portion being capable of expanding radially to a predetermined diameter with minor axial movement when subjected to internal pressure to provide a balloon, the balloon portion fixed to the distal end of the tubular flexible shaft and the distal end of the inner tubular flexible member; and   a transition portion at each end of the balloon portion for coupling the balloon portion to the distal end of the inner tubular flexible member and the distal portion of the tubular flexible shaft, the transition portion being capable of longitudinal extension in response to a minor longitudinal contraction at the two ends of the balloon portion to reduce the axial movement when the balloon portion is inflated.   
     
     
       2. The dilatation catheter of claim 1, in which the balloon portion is formed from a fabric substrate and a fluid impermeable elastomer. 
     
     
       3. The dilatation catheter of claim 1, in which the transition portion is formed from a fabric substrate and a fluid impermeable elastomer. 
     
     
       4. The dilation catheter of claim 1, in which the balloon portion is formed with radial crimps running length-wise about the circumference of the balloon portion. 
     
     
       5. The dilatation catheter of claim 1, in which the transition portion is formed with longitudinal crimps. 
     
     
       6. The dilatation catheter of claim 1, in which the balloon portion is formed with a plurality of circumferential crimps running length-wise and the transition portions are formed with a plurality of longitudinal crimps across the length of the catheter. 
     
     
       7. The dilatation catheter of claim 6, in which the baloon portion and the transition portions are formed from a fabric substrate and an elastomer. 
     
     
       8. The dilatation catheter of claim 4, in which the transition portion is formed from a fabric coated with an elastomer. 
     
     
       9. The dilatation catheter of claim 5, in which the balloon portion is formed from a fabric coated with an elastomer. 
     
     
       10. The dilatation catheter of claim 6, in which the crimps have a triangular cross-section. 
     
     
       11. The dilatation catheter of claim 6, in which the crimps have a curvilinear cross-section. 
     
     
       12. The dilatation catheter of claim 6, in which the crimps have a cross-section in the form of a frustum of triangle. 
     
     
       13. The dilatation catheter of claim 7, in which the fabric is polyester. 
     
     
       14. The dilatation catheter of claim 7, in which the polyester is coated with polyurethane. 
     
     
       15. The dilatation catheter of claim 1, in which the inner member includes a distal tip, the shaft having a distal transition portion, a proximal transition portion, and a balloon portion therebetween, the distal end of the distal transition portion coupled to the distal tip, the proximal end of the proximal transition portion fixed to the outer flexible shaft, and the balloon portion between the connecting portions. 
     
     
       16. The dilatation catheter of claim 6, further including a radio-opaque member to aid in positioning the catheter during use. 
     
     
       17. The dilatation catheter of claim 16, wherein the fabric substrate is a dacron fabric and the elastomeric material is a polyurethane. 
     
     
       18. The dilatation catheter of claim 2, wherein the fabric substrate is coated with the elastomer. 
     
     
       19. The dilation catheter of claim 2, wherein the fabric substrate is impregnated with the elastomer. 
     
     
       20. The dilatation catheter of claim 2, wherein the elastomer is in the form of an inner sleeve and an outer sleeve disposed about the fabric substrate. 
     
     
       21. The dilatation catheter of claim 3, wherein the fabric substrate is coated with the elastomer. 
     
     
       22. The dilatation catheter of claim 3, wherein the fabric substrate is impregnated with the elastomer. 
     
     
       23. The dilatation catheter of claim 3, wherein the elastomer is in the form of an inner sleeve and an outer sleeve disposed about the fabric substrate. 
     
     
       24. A dilatation catheter, comprising: a length of a tubular shaft of flexible material having a longitudinal axis;   an inner tubular flexible member coaxially disposed in the shaft and having a distal portion projecting therefrom;   a balloon portion formed at the distal end of the flexible shaft, the balloon portion formed with a plurality of circumferential crimps running length-wise being capable of expanding radially to a predetermined diameter with minor axial movement when subjected to internal pressure to provide a balloon, the balloon portion fixed to the distal end of the tubular flexible shaft and the distal end of the inner tubular flexible member; and   a transition portion end of the balloon portion surrounding the inner flexible member formed with a plurality of longitudinal crimps across the length of the catheter for coupling the balloon portion to the distal end of the inner tubular flexible member and the distal portion of the tubular flexible shaft, the transition portion being capable of longitudinal extension in response to a minor longitudinal contraction at the two ends of the balloon portion to reduce the axial movement when the balloon portion is inflated.   
     
     
       25. The dilatation catheter of claim 24, in which the balloon portion and the transition portions are formed from a fabric substrate and an elastomer. 
     
     
       26. The dilatation catheter of claim 24, in which the crimps have a triangular cross-section. 
     
     
       27. The dilatation catheter of claim 24, in which the crimps have a curviliner cross-section. 
     
     
       28. The dilatation catheter of claim 24, in which the crimps have a cross-section in the form of a frustum of triangle. 
     
     
       29. The dilatation catheter of claim 25, in which the fabric is polyester. 
     
     
       30. The dilatation catheter of claim 25, in which the polyester is coated with polyurethane. 
     
     
       31. The dilatation catheter of claim 24, further including a radio-opaque member to aid in positioning the catheter during use. 
     
     
       32. The dilatation catheter of claim 31, wherein the fabric substrate is a dacron fabric and the elastomeric material is a polyurethane. 
     
     
       33. A balloon catheter for introduction into a blood vessel, comprising: an inner tube having a longitudinal axis;   an outer tube in coaxial relation to the inner tube;   the inner diameter of the outer tube being larger than the outer diameter of the inner tube so that the two tubes form an annular space between the tubes, and the distal end of the inner tube extending beyond the distal end of the outer tube with the distal end of the outer tube sealed to the inner tube;   the outer tube formed of a flexible material and having a balloon portion and a transition portion at each end of the balloon portion disposed at the distal end of the outer tube; the balloon portion and transition portions formed from a fabric substrate and a fluid impermeable elastomeric material;   the balloon portion formed with a plurality of circumferential crimps running length-wise along the axis;   the transition portion formed with a plurality of longitudinal crimps across the axis;   the balloon portion adapted to be inflated to a predetermined diameter when subject to internal pressure to provide a balloon; and   the transition portions longitudinally extending to compensate exactly for minor longitudinal contraction at the two ends of the balloon portion when the balloon is inflated whereby the baloon portion is not displaced longitudinally in the blood vessel.